Tuesday, September 15, 2020

Cutting and Shaping

Below are a few pictures from progress on Nina's wing board. 

Profile shaped, outline marked: 

Table wire cutter setup:

Rough outline cut:

After cutting the outline with the table wire cutter, a few gaps became visible where the original foam blocks had indentations:

I filled the gaps with PU foam, which seemed to worked nicely.

After the fine trim of the outline with hand tools, I marked the rail lines, and then added a layer of 6 oz glass and 1/4 inch divinycell to the top. Since this is a wing board, a full sandwich construction which is typical for windsurf boards seemed like overkill. The board will not constantly slam into waves, so reenforcing the bottom does not seem necessary. However, a typical surf board construction, which uses just a couple of layers of fiber glass on top, would probably not have lasted long. Surfers stand on their boards only a few minutes each session, while Nina usually stands on her wing boards for at least a couple of hours per session. Add full-body pumps to get going to that, and the top would quickly delaminate. Therefore, I added a sandwich only to the top. The thickness of the hard PVC foam is twice of what's usually used in windsurf boards; thicker sandwiches are stronger. Instead of using vacuum, I just used a bunch of boards and weights to glue the sandwich foam on:

The weights seemed to work well enough:

Shaping the rails was the next step. The lines where the foam blocks were glued together were a bit harder than the foam, which made for some uneven sanding, so the shape is not quite perfect - but not too bad for the second board I ever built. Here's a view from the front:

A bottom view:

Between the step tail, rails, and plenty of nose rocker, the board almost looks more like a kayak than like a surf board.

In front, Nina wanted a concave bottom, which makes for smoother touchdowns and may also help getting the board out of the water. I first had to make a little tool to sand the concave:

Here's a closeup of the concave in front:
The next step will be to put the two US boxes for the track mount in. I prepared them today by encasing them in divinycell foam:

Putting the boxes in should be interesting. I've put tracks into 3 boards so far, but they were all existing windsurf boards. Routing the foam will be much easier than cutting through the sandwich, but require being more careful. I plan to put the boxes in so the tops are flush with the top of the foam, and then add one layer of glass to reenforce the track area. But the bottom will still be weaker than in the windsurf boards, so I'll add a couple of PU foam plugs below each of the boxes that connects them to the sandwich on top. 

Wednesday, September 9, 2020

Profile Cut

We got to use the foam wire cutter today, and it worked beautifully:

We cut a couple of profile templates out of cheap wood, which we then taped to the side of the foam blocks to guide the wire cutter. Cutting was easy overall, with noticeable slowdowns when the wire cut through the polyurethane glue between the sheets we had glued together. But with a bit of patience, the wire cut through the glue, too. Now it's a bit easier to see what we are building ... and Nina is starting to get quite excited.

There's a lot of rain in the forecast for the next few days, which means there will be little progress, since all the board building is done outside. Friday's weather looks nice, but there's also wind in the forecast, and ABK is in town for the annual camp, so we'll be at Kalmus. We won't do the ABK camp this year, mostly because it's run at a much smaller scale to allow for social distancing. We figured others can benefit more from ABK's excellent instructions than us (with more than 40 AKB camps between the two of us so far!). But we'll certainly stop by to say hello, and go foiling a bit.

Tuesday, September 8, 2020

Making a Foam Wire Cutter

 Today's project was making a foam wire cutter. Here's the setup:

I mostly followed the instructions at instructables.com/id/Hot-wire-foam-cutter/, with the main variation to use a battery charger as a power supply, as someone had suggested in the comments. Since I did not know which wire would work well with the battery charger, I ordered a $20 multi-pack of nichrome wire rom Amazon that contains sizes from 22 to 36 gauge. I started with the 26 gauge wire, which did get hot enough to cut foam, but only very slowly. So I switched to 24 gauge, which worked fine for the test  cut shown on the left. But before we can use it to dig out Nina's board, we'll have to make wood templates of the profile, which will be attached to the sides of the foam block to guide the wire.

Back when I built my first board, everything was shaped by hand - but the core was PU foam, which was really easy to shape. The XPS foam I'm using for this board seems a lot harder to sand, so the wire cutter will be a big help. Let's hope it works as planned...

Monday, September 7, 2020

Building Nina's Wing Board

It's been about 40 years since I last built a windsurfing board. That was tons of fun (and made relatively easy because the University of Konstanz offered a course, where they provided a room, ordered supplies, and gave some instruction) - so why not do it again?

Nina wanted to try a smaller wing board, since many wingers say smaller is better. Normally, we'd probably just take a trip to a place where you can rent a few, but this is not the best time for traveling. So - just getting a blank, putting tracks in,  and wrapping it in fiber glass can't be too expensive, right? Especially since Nina wants a tiny board - only about 160 cm long. No need for a mast track of foot strap plugs, either!

We priced it out the easy and "perfect" way - a pre-cut, custom designed blank shipped to our door, S-glass and carbon, and a few other goodies. That came out to about $900 for material. Too much!

Back to the drawing board. Insulation foam from the local hardware store, cheaper fiber glass, no carbon, and a few more simplifications dropped the price to about $350. Sounds much better! 

Once we had discussed this, Nina asked about once per hour "when are we going to the hardware store"? So we got started, and three days later, her board came into existence:
It's in there! I just have to cut it out, put foil tracks in, and wrap it up in some fiber glass. Granted, I work on a computer and not with my hands, so this will be slow going, but there's a reasonable chance this will get done before next year. If the little boss does not make me work too hard on this, I'll keep you posted about the progress here, and share some details about what I did, and what I learned.


2 inch x 4 feet x 8 ft insulation board (2)
Electric foam cutter (and old socks to clean it while cutting)
Gorilla glue, 8 oz bottle
Lots of weights, clamps, and wood


  • Check the foam carefully in the store. The pieces I used had a shallow groove on one side that I had not seen, which required a "Gorilla glue injection" after the first glueing
  • Clamps work better than weights. We tried weights for the first two pieces we put together, but even a couple of hundred pounds is nothing to expanding Gorilla glue. In the picture, the third piece that allows for decent nose rocker is glued on, and the clamps help things together much better. A few more pieces of wood to also compress the middle might have been useful.


Sunday, August 30, 2020

Fun in 4 to 30 mph winds

 We used to think that Kalmus in west wind is pretty much unsailable. A few times when we got caught when the wind turned from WSW (which is great) to W while windsurfing, we did not like it, not one little bit.

But it was a beautiful sunny day today; the wind was from the west; and BaHa did not look great because the wind was a tad strong for foiling, but predicted to drop - and the launch tends to have tons of greenheads this time of the year. Ever since Nina got her wings, she does not really mind gusty wind anymore - so to Kalmus we went.

To make a long story short, I'll just show you a picture with the GPS tracks and the wind readings for the time we were on the water:

The meter showed lulls of 4 mph and gusts to 30. The lulls were not quite that low on the water, but close enough, and the gusts felt like at least 30 mph. But we still had plenty of fun. When the wind averages dropped to 12 mph at 12 noon, Nina switched from her 4.2 m wing to the 5.4. I stayed with my 5.6 Freek, which I like more and more for foiling. I had to wait for wind to get going every now and then, and even came off the foil in lulls once or twice, but I was foiling most of the time - at times barely, at other times barely holding on, but always having fun. Here's a short video:

Thursday, August 27, 2020

I Wish

 Eddie recently posted a picture of me foiling at Kalmus:

He said in the comments that I was shredding. I wish!  This picture was taken when I came into shore and stopped in water too shallow for the mast. So I killed speed by going upwind, and tried to tilt the board sideways so the foil would not hit the ground, before I fell off backwards. But the picture looks cool.

The board in the picture is my new Progressive Riser 6.10 foil SUP that I bought for winging. This session was my 3rd on the board, and the first were I actually had fun. The board supposedly has 130 l, which should be plenty, but most of it is in the back, and the nose is 1 1/2 feet shorter than on my zombie foil board. Slogging the board is physical exercise, and not the fun kind. But when nicely powered as in this session, it's an awful lot of fun - less sensitive to the wind pushing it around, and very turny. That was a great session.

Yesterday, I took it out for a wing session -  my first ever. Most of the session was spent walking back upwind, after going downwind while trying to stand up. It took more than an hour to figure out how to sail upwind (not on the foil), and about as long to get two very short foil rides. The second time, I had my feet placed a bit wrong, which resulted in very rapid curves as soon as the foil came out, followed by the crash. But this was about what I had expected for the first session. Winging is not easy! It will take a few more sessions before I get an idea if I like it. I would not have even tried it if I had not seen my lovely wife having fun on the same wing in 14 to 30+ mph winds. She makes it look so easy - I wonder if it will ever be that easy for me. Here's a short video of her foiling through a jibe:

Saturday, August 22, 2020

GoPro GPS and Race Render for Jibe Analysis

A few days ago, Nina pointed out that GoPro cameras are not that expensive anymore. Since I always was curious how much speed she kept in foiled jibes when winging, and GoPros that are newer than our ancient 3+ have a built-in GPS, we just had to order one.

After a couple of snafus with non-fitting accessories and rotated videos, I finally got some useable footage from the camera yesterday. Here's a short video:

I can't say that I am a great fan of the GoPro Hero 7 Black. It's much heavy and slightly larger than the old GoPro 3+, and gets less than half of the battery life, even at low resolution and with image stabilization turned off. The desktop software that GoPro provides to get the GPS speeds showing in the video is poor (if you ask me about it on the beach, you may hear less "friendly" words).  But fortunately, there's very nice third-party software available that even runs on Macs: Race Render.  Race Render makes is very easy to add different gauges and graphs to the video that show the data from the GoPro GPS. You could also use an external GPS, but that would require synchronizing, which could be a bit difficult. 

Here's a screen shot:

The movie from the GoPro 7, which I had mounted on top of my helmet, is shown as a small inset at the bottom right. The main picture is from the old GoPro 3+, mounted at the end of the boom with a ClewView. Race Render makes it really easy to synchronize the videos.

On the top right is a heading indicator; the display is adjusted to that the top is dead downwind (we'll get back to that in a minute). Below is a speedometer, and below that a speed graph. The picture above is from the jibe entry, shortly after unhooking and starting to carve downwind. The next picture is a second or two later,  after oversheeting a bit:

At this point, my speed has already dropped from 30 to 24 mph. The next picture is dead downwind:

I've started to open up the sail for the sail flip; speed is down to 18 mph.

In the picture above, I'm just letting go with my back hand. The picture below is in the middle of the sail flip:

By now, my speed is down to 15 mph - I've already lost half of my entry speed. The speed will drop a bit more before I grab the boom on the other side:

13 mph is the lowest speed in this jibe, according to the GoPro GPS. I was also wearing a Locosys GW-60 GPS watch, which reported a very similar minimum speed of 14 mph for this jibe.

I was doing sail-first jibe as a practice for foil jibes. The image above is just as I am switching my feet. I'm approaching the new beam reach and have power in the sail again, so I'm not loosing any more speed.

A few seconds later, hooked in again and getting into the front strap. My speed is already picking up again.

There are a few things that I could have done better in the jibe, but that's not what the post is about. I mostly wanted to share how useful the built-in GPS from the GoPro could be together with the video when working on improving jibes, and that Race Render is a pretty cool tool for this. There's a free version that has most of the functionality, as well as several paid versions that allow customizations and removing the Race Render logo that the free version puts in the movie. 

Wednesday, August 12, 2020

No More Rail Rides!

 I wanted to do rail rides ever since I learned windsurfing a few decades ago. Eventually, I learned to do them on longboards thanks to ABK Boardsports clinics. 

Foiling has replaced longboarding on lighter wind days now. But it seems my body still wants to do rail rides:

Unfortunately, my body forgot to tell my brain in advance, so it was completely unprepared and panicked:

I can highly recommend to not try this kind of crash. I hit the water in front of the foil, and the board and foil were still moving forward. Fortunately, I foil slowly, so the foil hitting my leg did not really hurt.

Apparently,  this only encouraged my body to try again (of course, also without advance notice to the brain, which would have vetoed the idea). This time, it was in the middle of a sail-first jibe try:

This clearly was over-ambitious: not only did my body try a leeside rail ride this time, which is harder than the regular rail ride - but it also went for the one-footed, one-handed version. As soon as my brain noticed what was going on, it ordered my body to bail, and the board continued on it's own:

At least this time, I fell away from the foil, so the crash was harmless. But seeing that my body apparently was up to no good, I decided to not try any more jibes that session. So the foil jibe remains elusive. But on the upside, I discovered a new way of messing the foil jibe up. Perhaps if I remember to not do rail rides on the foil, I can get a step closer to making one! It would also help to place the backfoot more to the rail, and to not let the mast escape to the outside of the turn. The mast on the outside probably caused the leeside rail to come up, and the foot placed too close to the center meant I had no leverage to push it back down. Maybe next time...

After the session, I watched Spencer and Coon foiling a bit. Both of them had foiled just a few times before, and while the both got some decent runs, at other times, their attempts looked more like attempts to tame a wild bronco. That looked awfully familiar, and made me feel a tad better (or perhaps the after-foil beach beverage was to blame for that part). 

Here's a short video from after the rail ride attempts:

Sunday, August 9, 2020

Foil Jibe Tips

 After a year of foiling, I still struggle with the jibes. The goal of foiling through jibes on a regular basis remains elusive. Of course, I have all kinds of great excuses. My foil board is narrow - only 22 inches (56 cm) wide. Just about every article about foil gear in the German "Surf" magazine states that wider boards are easier to jibe when foiling. But this excuse seems a bit lame when I look at my lovely wife, who foiled through jibes on a regular basis .. on her skinny 90 l freestyle board. So I won't even bore you with my other excuses, which are even lamer.

Instead, I'll share a few insights I had after watching a couple of jibe tutorial videos from Sam Ross. Here's the step jibe tutorial:

The jibe is quite similar to a jibe on slalom gear. One of the differences is that he sails clew first briefly after stepping to stabilize; that's quite common for foil jibes even among racers, but unusual on slalom gear.

Overall, Sam's technique is very similar to what Nico Prien shows in his jibe tutorial video. One thing that looked very familiar in Nico's video was the "oversteering" mistake he shows at 5:44 in the video:

This has happened in many of my jibe tries: the board just keeps carving, and the foil seems to be pushing the board into an even harder carve when the windward rail catches the water. Nico points out that "you need to actively balance the bank" - in other words, flatten out the board to stop the turn.

I started trying step jibes on the foil, but moving the feet and the rig at the same time while the board is in the air always seemed a bit too much for me. Largely based on Andy Brandt's suggestion at the ABK camp in Hyannis last year, I switched to sail-first jibes instead, where you sail out in switch stance and move the feet later. I have no problems with sail-first jibes on windsurfing gear, but on the foil, they seemed just as difficult as step jibes. So maybe the tutorial video from Sam Ross, who calls it the "strap to strap gybe", would help:

Comparing the two Sam Ross jibe videos, there's one big difference I noticed: the position of the mast during the sail flip. In the step jibe, the mast is moved to the outside of the turn:

That's the same when windsurfing. But in the sail-first foil jibe, the mast does not move to the outside - it stays perpendicular to the board:

Since the board is banking into the turn, the mast is also leaning into the turn a bit. When teaching the jibe at the ABK camp last year, Andy Brandt said we should keep the mast to the inside of the turn. I guess this is what he meant! I over-interpreted his instructions, and thought that the mast should point even further to the water - something that's hard to do if you are not oversheeting.

Interestingly, during the sail-first jibe when windsurfing, moving the mast to the outside of the turn is not a problem at all. But the foil is much more sensitive, and moving the mast to the outside when letting go with the back hand immediately changes the carve, and makes it nearly impossible to complete the jibe dry.

When thinking about the instruction videos, I was wondering why foil racers always seem to step jibe, while many early foil jibe instruction videos used the sail-first jibe instead. Both Sam's and Nico's tutorials provide a clue when they talk about slicing the mast forward: on race foils, foilers are often going faster than the wind. That makes opening up the sail impossible, since you'd just get backwinded. On the foil, that means that the foil would probably shoot up and out of the water for a spectacular crash.

The sail-first jibe requires that you are going slower than the wind, since the wind pressure from behind flips the sail. In contrast, a step jibe also works when the apparent wind is coming from the front because you are faster than the wind; you just have to make the sail flip similar to the sail flip in a helicopter tack.

Both Nico Prien and Sam Ross are on race or freerace-type foils and boards. In Sam's "How to go Faster on the Windfoil" tutorial, he reaches speeds of 26 knots. But typical speeds on freeride foils like the Slingshot Infinity 76 or 84 are much slower. My typical cruising speeds on the i84 are around 10-12 knots, so I'm going slower than the wind speed most of the time. That makes the sail-first jibe possible, and it has one big advantage for "marginally coordinated" foilers like me: I can concentrate on one thing at a time, and don't have to move the sail at the same time as I move my feet. Time to go foiling!

Tuesday, August 4, 2020

Fun On The Slapper

Nina winging in 30 mph. Picture by Eddie Deveraux.

It was windy in Kalmus yesterday, with averages in the low 30s and gusts to 40 mph:
iWindsurf meter readings for Kalmus 8/3/2020

We went in the afternoon, when the wind was nice and steady. Nina wing foiled for almost 3 hours, and reported that she may have gotten closer to the upper end of the wind range for her 4.2 m wing. It was fluttering at times, and upwind angles were a bit compromised since she could not move the wing to the side as usual - too much power!

I decided to go for a session on the "slapper", as Australian wind foilers like to call windsurf boards. But since I'm not the biggest fan of high tide slapping in Kalmus WSW voodoo chop, I went over to Egg Island for some really flat water. I tried to get a few guys to come along, but without success - Gonzalo, who had indicated interest, decided to rig down from 4.7 to 4.2 after a few trial runs, and I did not have the patience to wait for him. High tide is the best time for speed runs along the sand bar, and the tide had been dropping for a while already! Besides, he had sailed Lewis Bay on a longboard many times, so he knew the way.

I ended up having the "kiddie pool" at Egg Island entirely for myself. I'd rigged my old 5.5 m Matrix sail since it has a ton of high end, and that was a perfect choice. The wind behind the sand bar tends to be a bit lower, and the flat water also allows for larger sail sizes. How flat, you ask? Have a look:

I was working on my sail-first jibes for foiling, which are a ton of fun in flat water. I learned on reason not to let the mast get way to the outside of the turn: the sail is a lot heavier than the freestyle sail I normally use, and when whipped around by the strong wind, was too heavy to be pulled back in. That resulted in a few fun high speed crashes before I got my act halfway together. Still needs a bit of work, since my speed dropped from a 30 knot entry speed to 12 knots after the sail flip. But it was fun, anyway!

I ended up getting a 32 knot top speed on my GPS watch, which is the fastest I've ever gone on a freestyle board. The little 22 cm weedie from Maui Ultra Fins held astonishingly well, even though it's the freeride version, not the speed or slalom version.

After about 2 hours, the tide dropped low enough to expose parts of the outer sand bar that is submerged during high tide. It's oriented at a right angle to the WSW wind, so it creates a nice setup to work on alphas (500 m runs with a jibe in the middle, and the ends of the run have to be within 50 meters). For that, I reverted back to the step jibe:

I just did a few tries before heading back to Kalmus through the chop. Since the wind was still up, going back upwind was super easy. Here are the GPS tracks:

By chance, the session ended up counting for the GPS Team Challenge, since Kipps set a couple of nice PBs sailing on the other coast.  Together with a few decent numbers from the day before,  that put our team on the #2 spot in the monthly rankings:
Unfortunately, that won't last, since other teams will post better sessions over the rest of the month. But I'll enjoy it while it lasts!

Friday, July 31, 2020

Pushing Foil Limits

It's been a hot and windy July. I've been on the water for 19 windfoil sessions, and windsurfed four times, often when the wind picked up so I could plane on a 5.0 or 5.6 m sail.

Yesterday was a day with a mediocre forecast, which tends to make for great foil days. I started foiling when averages were around 13-14 mph, which made it quite nice with a 5.6 on the i84 foil. Here are the GPS tracks for the day:
The flat water was nice for tacks, and encouraged me to try a few sail-first jibes. I ended up with a few reminders why you should not let the sail get to the outside of the turn. I also discovered a disadvantage of the sail-first jibe on the foil: if the board gets all wobbly after letting go of the back hand, crashing safely gets much harder since only one hand remains on the boom. It took me a couple of tries to understand that.  The first one was a warning which I ignored; the second one was harder to ignore, since the board tilted sideways. That put the foil exactly where I was falling. Fortunately, I have a hard head even without a hard hat, so I did not even bleed after hitting the back of my head on the foil. It killed my appetite for additional jibe tries in the same session, though.

Instead, I headed into the flat water behind the Hyannis Port pier, and pushed the foil a bit faster than I had ever foiled before. By then, the wind had picked up into the mid-20s, and it was time to head back in. The strong wind made for a very interesting ride in steep chop. And then, it got even stronger, hitting 29 mph averages and gusts in the low 30s. Waterstarts, which were difficult, one-footed, and only in gusts at the beginning had long changed to the two-footed, "keep the thing controlled at all cost!" variety, were not placing enough weight on the front foot meant I was foiling before I was even over the board. But now, I was either getting catapulted right away, or the wind just grabbed under the board and flipped it over, completely ignoring the heavy aluminum foil. Not even body-dragging with one foot on the board, my usual fail-safe when things get crazy, worked - board and foil were blown out of the water  and flipped over within a couple of seconds. Eventually, I discovered that body-dragging clew first from the leeward side worked, with the added benefit of being an excellent workout. After dragging a quarter mile downwind, the wind finally let up enough so that I could waterstart again, and foil in the last bit, with a fully flagged out sail. Meanwhile, Nina, who had been wing foiling on her 4.2 the entire time, stuck around and enjoyed that the strong wind let her foil through her jibes with ease. Maybe I need to get one of these things ... but I have the suspicion it just would not work quite as well for me.

Well, an interesting session it was, and certainly a memorable one - but also a lot of fun.

Saturday, June 27, 2020

Different Toys

It's raining today, and I'm glad to get a day off the water. We've been playing for 4 days in a row now, so I need a little break! Part of the reason is that I finally dragged the slalom gear onto the water again yesterday. After mostly foiling in the last few weeks, the 7 m race sail felt sooooo heavy! The rig probably is about twice as heavy as the 5.0 m freestyle sail I use most of the time .. until the huge luff sleeve fill with water, and it gains an extra 50+ pounds. The wind was mostly around 17 knots, and my 99 l board felt a bit small in the lulls, but the gusts were fun. Eddie took a few pictures:
Nina was on the wing - her sixth session in high winds:

I was foiling the three days before that day. The wind was light when we came to the beach on Thursday, so I wanted to use my bigger Infinity 84 front wing. However, that wing does not work well in my old slalom board anymore: the fuselage with the extra hole for a "D" position broke into two pieces recently while foiling. So I used my old Fanatic Skate 110, to which I had added tracks. It was quite surprising how much more concentration the foiling on the Skate needed - 5 cm less widths and ~10 liters less volume make a surprising difference. On the Skate, I had to move my feet as far to the outside rails as possible to keep things under control, something I never have to do on the Warp. Upwind angles also were a bit worse than on the slalom board with the Infinity 76 front wing. But since the wind increased and I was well powered to slightly overpowered, tracking upwind towards the Hyannis Port Harbor entrance was not big deal. 

The day that I was on the i84, Nina also started windfoiling on the large foil, with a 5.2 m sail. When the wind picked up, she was overpowered, and did not like it one little bit. But on the bright side, that meant she had enough wind to go winging, which she did. I stayed on shore to take some pictures and videos of her (unfortunately with a rather small zoom lens) - here is one:

Monday, June 22, 2020

The Wing Thing

Nina read about the wing thing, so she had to get one. A short trip to Phil at Inland Sea, and a couple of hours, she was on the water with my big old SUP:
There were a few upwind walks involved in this session.

A few days later, the fuselage on my foil snapped mid-session. I had added an extra hole so that I could move the wing more forward on my old slalom board. That gave me a much more balanced setup, and worked fine for about 50 sessions. But it left one extra hole between the front wing and the mast, and that's were the fuse broke. A trip to Inland Sea in West Dennis later, I had a new fuselage - and a JP SUP that's well suited for wing foiling.

Since then, Nina has been winging three times. The first session was in 25 mph averages on my old Skate 110, and she managed to get up on the foil a few times. That was a success.

Nina's second wing foiling session was at in lighter wind at Pleasant Bay. This one was bit more frustrating, with only short runs on the foil and not much progress. But we saw Jerry Evans on his setup, which was pretty impressive. I was barely able to get up on the foil on my 5.0 m sail, but Jerry was foiling the entire time on his 4.2 m wing. He was also having a total blast. One of the things I had read about winging was that wing foiling needed more wind that wind foiling - but that clearly was not the case here. 

The next few days saw lighter wind, which Nina used to foil on the new JP SUP with a rig. That was a worth-while exercise, since the board behaves quite differently from our windsurf boards. The foil is further forward under the board, the mast base is further back, and the board is shorter, has round rails, and a lot of rocker. That means the technique to get going is surprisingly different. Any sideways pressure while pumping quickly results in a direction change, so I had a hard time to get the board accelerate to take-off speed in light wind. But Nina figured it out, and managed to foil in 11-12 mph wind with her 5.2 sail. 

Her third day of wing foiling was in 16-22 mph averages at Kalmus. The progress was quite astonishing - she was always foiling, apparently 100% in control, when going out against the waves, and often also when coming back to shore. That's a bit more difficult even when foiling with a windsurf rig, since the waves coming from behind affect the large 84 cm foil a lot, pushing it up and down. But at the end of the session, even her inbound runs look about as good as my windfoiling runs (after ~80 sessions so far). She even got a few dry jibes, although not yet foiled through. 

What amazed me most about her three sessions was the range of the wing. The same 4.2 m wing worked perfectly fine in 16 mph averages and in 30 mph gusts. With windsurfing sails, the same range would typically require 3 different sizes - at least. Windfoiling, I could probably get away with just one sail (a 5.0), but the 16 mph are close to the low end, and in 30 mph gusts, things would start to get quite "interesting", and crashes would become more frequent. But on the wing, Nina felt perfectly comfortable over the entire range. Power can be controlled very easily with the wing, it seems - and since the power is not transmitted over the rig towards the front of the board, adjusting power does not lead to the board going up or down, which tends to happen when sheeting out or in while windfoiling.

So at some point in the future, I'll probably have to try this wing thing myself. I don't think it will happen with the 4.2 wing - I'd need a lot of wind, which would also mean a lot of chop at Kalmus, so I'd just be falling off the board all the time. But besides that, Nina would want to use the wing herself, and preferably with the JP SUP (at least until she gets better and may want a much smaller board). So we'll probably have to wait until we get a second wing - a bigger one for Nina's light wind fun, and for me in somewhat stronger winds. 

Thursday, June 4, 2020

The Sleeves Come Off

This spring on Cape Cod has been a bit chilly, but that's finally over. The water in the middle of Nantucket Sound now shows temps of 60F, and it feels warmer near shore. Time for 2 mm short sleeve suits! That's what I used yesterday for a 2 hour foil session, and it was warm enough - despite plenty of crashes and a few times where I had to wait for wind when waterstarting. Here are the tracks:

The wind would not have been great for windsurfing, dropping from 22 to 14 and then going back up for 20 for a little while. But the foil has a larger range, so I was fine on the 5.0 the entire time, with just a couple of minutes of shlogging when the wind was lowest. Nina eventually joined me in Hyannisport Harbor, and really liked the flat water. She did a few nice foil jibes, including a duck jibe that she planed through, and almost foiled through. I worked on my tacks, after seeing how foil racers can actually plane through tacks. I did not get anywhere close to planing through, but it still felt cool to carry a couple of knots through the entire turn.

With the wind playing the typical early-summer up-and-down games, we've been foiling a lot, and it has been a blast. One time when I was just getting going on the foil, a kite surfer was coming my way. When he saw me, he pretty much came to a dead stop to let me get going, even though we where at least 300 feet away from each other. Probably not necessary, but a very nice gestures, and much appreciated. Thanks! 

Monday, May 25, 2020

When Doctors Are Wrong

Well, the windsurfing and foiling has been good - we've been on the water 5 of the last 7 days, with three sessions that I'd label as "excellent". But we stayed home today, and I discovered a few things that called for another COVID-19 related blog post. Here we go:

Medical doctors are regular people - they make mistakes, and they do not know everything. That's fine ... unless they forget it, and insist that they are right, which happens all too often. For me and my lovely wife, the "hit rate" from MDs is somewhere around 50%, at best. But I won't bore you with gastritis being diagnosed as "kidney stones or maybe appendicitis - go to the emergency room for a CT scan!", or carpal tunnel syndrome mistaken as vitamin B12 deficiency, or plenty of other such stories.

Instead, I want to look at an example about how medical "experts" just "know" that COVID-19 is transmitted "almost exclusively" or "always" through "large droplets", even when there is plenty of evidence staring right at them that this is NOT the whole explanations.

The issue started when I followed up on a couple of links in a study titled "Avoiding COVID-19: Aerosol Guidelines". References 65 to 68 in this article link to three different events where a large number of choir members got infected during choir practice or performances. I had written about the choir in Washington State already, but the others were new to me. They describe two choirs in the Netherlands, in Amsterdam and the town of Heerde, where 40% respectively 75% of the choir members contracted COVID-19. I then did a quick search for similar incidents in Germany, and found three similar choir events: in Berlin, Hohenberg, and Stade.

What really got to me was the statements by a German professor, Christian Kähler of the Military University, Munich, as reported by The Guardian. He did some experiments to see how far he could see air movements from the mouths when singing; found that the air moves less than 2 feet; and concluded:
"However, we also found out that singing is quite safe. It was not the cause of the outbreaks of Covid-19 at these concerts."
 That statement goes against a lot of evidence, but it is easy to understand where he is coming from when we look at another statement he made:
"I have been studying how droplets and aerosols behave for decades and I was very doubtful that musicians and singers were spreading the virus."
So, he was very skeptical, and set out to prove his point. Never mind that you actually cannot prove a negative - his study was deeply flawed because he only looked at air movement - he did not even look at aerosols! In fact, his own institute's web page that reports the experiment results explicitly states that not only that good ventilation is essential to avoid infections, but that the air should be flowing vertically, from inlets on the floor to outlets in the ceiling.

So Kähler concludes that all the infections that happened during choir practice must have happened when people where in close proximity - less than a meter, according to his own data. But the very short forward air movement that he takes as evidence that "singing is safe" would not even reach the person in front of a singer! So practically all transmissions would have to happen during breaks, when participants get coffee and mingle. The one or perhaps two initially infected people would then have to sneeze or cough at dozens of others in very close proximity. The "direct droplet" infection route even requires that some of the sneeze droplets hit the other persons mouth, nose, or eyes directly .. dozens of times here. Never mind that sneezing is quite rare with COVID-19, and not even listed as an official symptom!

Old "expert" guys like Kähler who simple refuse to consider new evidence, and rather direct their research efforts only to prove that what they always have said must be right, are very dangerous. They remind me very much at the doctor who treated my father when his dementia got bad. The doctor was the top expert for Alzheimer's in Germany, so he diagnosed my father with Alzheimer. He gave him psychotropic drugs, which perhaps would have been ok if the diagnosis had been correct - but they put my father into a catatonic state. Weeks later, other doctors correctly diagnosed my father with the second-most common dementia, Lewy body dementia (LBD); one characteristic is that LBD patients react very badly to psychotropic drugs.

Medical doctors who re-iterate the "common knowledge" that COVID-19 is transmitted by "large droplets" are at least as dangerous as my father's doctor. My father eventually recovered from most of the side effects, but in several of the choirs listed above, one or more members or their spouses died from COVID-19. It is very likely that the primary mode of transmission was long-distance transmission through aerosolized virus particles. There is plenty of science that supports this - studies that have shown that patients emit virus when talking; studies that show the particles can remain airborne for extended times, and that the virus remains infections in airborne particles for hours; studies that show that loud speaking and singing can release thousands to tens of thousands virus-containing droplets; and studies that show that direct inhalation is actually the most effective way of getting infected (check the summaries and links in this article for details, or various posts on my COVID-19 blog).

The science is clear: there is overwhelming evidence that aerosol transmissions can cause COVID-19 infections. Even with aerosol transmissions, staying 6 feet away from others dramatically reduces the chance of infection - but if you are indoors with many others for a longer period of time, and there's a lot of talking or singing going on, that's not enough, and a substantial chance of infection remains.

Some of the basic underlying science has been known for years. Some of the COVID-19 specific information has only become available in recent weeks. Unfortunately, a lot of the information at the "official" sites like the CDC, WHO, and Germany's RKI still focus mostly on "droplets made when an infected person coughs, sneezes or talks", and elaborate that "these droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs."

One often-heard argument against updating these guidelines is that "there is no proof of aerosol transmission". That is mostly true (although there is plenty of circumstantial evidence) - but there is also no firm evidence of droplet transmission. If anything, the available evidence indicates that indirect droplet transmission ("fomite" transmission) only plays a minor role. But besides a few experts like Kähler who are unable to change their minds "just because" of new evidence, there's another factor that makes this unlikely: concerns about aerosol transmissions may keep people out of restaurants and other indoor spaces, and thus work against "restarting the economy". But so will increasing case numbers that are partly due to misinformation!

Wednesday, May 13, 2020

Nice Distraction

A lovely little distraction today:
First time windsurfing in almost 2 months! Flat water, averages in the low 30s, sun, and warm enough - finally, everything came together. After a couple of hesitant turns, I even remembered how to jibe again. I took the "cheater" gear (Skate 110, Idol 5.0), since I'll need a few more sessions to be fit enough for a speed session. But 29 knots on freestyle gear feels plenty fast.

Monday, May 11, 2020

When Looks Matter More Than Lives

He never understood why testing is important. However, he is very concerned that it will "make ourselves look bad". He has access to all the scientists at the CDC, NIH, FEMA, and whatever government agency he wants, but the only thing he can think of is this:
"But they think they're doing it because it'll hurt me, the longer it takes to — hurt me in the election, the longer it takes to open up"
Have a quick look at the countries that lead the "COVID-19 death chart" - the countries with the most COVID-19 death per million inhabitants:
 All the countries at the top did not understand the importance of testing until it was too late. Several of them (the UK, the Netherlands, and Sweden) tried to mostly ignore COVID-19, and only keep "old and sick" people inside. It failed miserably every single time. Most of the countries in the list had to issue "stay-at-home" orders that were much more severe than those in the US - Spain, for example, had 30,000 road blocks to keep people from driving, and kids were not allowed to leave home at all for many weeks. Here is a graph that shows how COVID-19 "surprised" Spain:
The death curve follows the cases curve with just 2 days delay. In well-managed countries, the time between first symptoms and deaths is about 19 days. Even with allowing a few days for testing, the delay should be at least 2 weeks. Spain got blindsided, and paid a very high price for it. By the time they knew that they had a problem, millions were already infected.

In countries that had testing ready, the death toll was a lot lower. Examples include Germany, Austria, Australia, New Zealand, and Taiwan. In many of these countries, the epidemic started to slow down even before the first government measures were taken: when people heard that others were dying, and saw how quickly case numbers rose, they started to be careful, going out less and keeping their distance. When someone had symptoms, they knew that they should stay home so they would not infect others.

No ramping up testing quickly enough is much worse than just covering your eyes and hoping that "it will just disappear". It has cost many lives, and continues to cost many lives. The deaths are noticed whether there are tests or not; without tests, they instill even more fear. Fear keep people at home, away from flights, restaurants, and stores; it kills the economy, even without stay-at-home orders.

The only way out for the US without many hundreds of thousands of deaths, and many months of misery, is a massive ramp up in testing. "Test and track" is important, but tracking COVID-19 infections is extremely challenging because many infections happen before symptoms, or are transmitted by people who never get symptoms. In view of the realities in the US, test and track alone will not allow a "return to normal" - not even together with "6 ft social distancing". But repeated testing on a very large scale would be one thing that might actually work in the US.

It's not about looking good. It's about containment without sacrificing hundreds of thousands of lives.

Monday, May 4, 2020

Pants on Fire

"We’re going to lose anywhere from 75-, 80- to 100,000 people," Trump said. 
A day or two later, when the New York Times presented evidence that the White house had been warned about a much higher death toll, the White House immediately rejected the report. According to an NPR article, White House spokesman Judd Deere said:
 "The president's phased guidelines to open up America again are a scientific driven approach that the top health and infectious disease experts in the federal government agreed with. The health of the American people remains President Trump's top priority"
 Let us do a quick reality check. The "top health and infectious disease experts in the federal government" are working for or with the CDC. The CDC maintains a web page that lists a number of different computer models, and explains clearly why forecasting COVID-19 deaths is critical.

The web page also includes a link to a downloadable spreadsheet file that contains the numbers for all the models listed. I looked at some of the models (which now do not include the terrible IHME model anymore), and then downloaded the data file to have a closer look. Some models only predict one week into the future, but most models predict between 4 and 7 weeks ahead. Here are the total numbers of COVID-19 deaths that the models predict:

Projected COVID-19 Deaths
CU-80 contact
CU-70 contact
CU-60 contact

There is quite a variation in the predictions, which range from 119,337 deaths to 336,930 deaths over the next 4-7 weeks. 

Even the most optimistic model predicts close to 120,000 COVID-19 deaths. On average, the models predict about 200,000 deaths; half of the models predict more than 200,000 deaths. There is not a single model that supports the numbers Trump gave; all numbers are substantially higher. A "scientific driven approach" would list the range that the models indicate, perhaps leaving out the highest and lowest predictions: 135,000 to 242,000 deaths.

Note at all of the model predictions cover a period shorter than the next 2 months, and that all models still predict a substantial daily death rate at the end of the prediction period. In my model runs, the total deaths toll at the end of 2020 was about 50% higher than for the next 6 weeks. Clearly, the overall expected death toll in 2020 is even higher than the numbers in the table, quite possibly twice as high.

Furthermore, most of the models assume that social distancing measures remain in place. There is absolutely no doubt that COVID-19 transmissions and therefore deaths will increase when states "re-open", as many states have started to do. Nobody knows exactly by how much, but even a modest increase of transmissions by about 20% would result in more than 400,000 additional deaths.  A more dramatic increase could lead to more than a million additional deaths in 2020. The only thing that will hopefully prevent such an enormous increase in deaths will be state governors who "lock down" states again when they see case numbers increasing. But it looks like they will have to do so against the resistance of the White House.

Friday, May 1, 2020

Pictures Tell The Story

On the bright side, I have finally been back on the water. It was a short foil session where the wind dropped, and my finger tips hurt the entire time because it was a bit cold, but it was sunny, and I got flying a few times. It was pretty much exactly one year after last year's disaster session,  so we'll count it as a big success.

On the not-so-bright side, it seems the US is largely ready to give up the fight against COVID-19. The federal guidelines on social distancing, meager as they were, have expired, and 30 states have announced "re-opening" plans. The likely result is at least 700,000 deaths from COVID-19 in the US, and possibly more than a million. Time to switch to picture mode.

The model that the White House loves predicts zero daily COVID-19 death by the end of June. "It will just disappear".

Well, it did disappear in China. The curve above is for the Hubei province where Wuhan, the original epicenter of the epidemic, is in. The super-smart scientists at the IHME figures that it must just happen the same way in the US.
That's an overlay of the two graphs. Quite a clear picture, right?

Let's have a quick look at the streets in Wuhan during the lockdown:

They were completely empty. Private traffic was verboten. Nobody was allowed to leave the city.

How about the US? Here's an image from Atlanta, a city that has a lot of COVID-19 cases and death:
Not empty. On Cape Cod, the rentals for summer guests are full, and the streets are as busy as in any other year. Beaches are crowded, but not yet as crowded as in California:
Surveys show that many people in the US don't bother with masks. Pictures show the same:
About a month after "social distancing" was recommended in the US, it is ignored by many.

Most flight have been canceled, but some flights still operate, and leisure travel is allowed:

For comparison, China increased the strictness of measures against the spread of COVID-19 several times in Wuhan. About a months after the first measures, teams were going door-to-door to check Wuhan citizens for COVID-19 symptoms like fever:
Anyone with symptoms was put in quarantine camps, and released only after two successive PCR tests came back negative after at least 2 weeks.

I am not advocating the same measures in the US. But it is important to understand that they were much more drastic, and therefore much more effective. Some measures remained in effect after the eventual "re-opening":
Meanwhile, the governor of Massachusetts has deemed landscaping an "essential business" that is allowed to ignore the stay-at-home order. God beware the horror of overgrown lawns! Priorities are priorities.

The result is quite predictable:
About 6 weeks after the federal guidelines were announced, and more than a months after most states have issued "stay-at-home" guidelines, the number of cases per day is almost unchanged for the peak.  Compare this to the very rapid decay for China in the second model - there really is no comparison. The IHME model is 100% based on the assumption that the "Wuhan curve" applies to the US. That's a 100% wrong assumption. The model is braindead. Worse, it appears to be intentionally misleading by predicting a completely unrealistic low number of death.

Wuhan and New York City both have about 10 to 11 million inhabitants. New York City ended up with a much higher number of COVID-19 deaths, and a higher infection rate. China prohibited all travel out of Wuhan until the number of cases was near zero; NYC residents are, and always have been, free to travel wherever they want to. But the so-called president calls armed and masked protesters like these "good people":

He encouraged protests against his own guidelines while they were still in effect:

The US had at least one month more warning about COVID-19 than China had. Now, the US has 14 times more COVID-19 deaths than China, and is on track to have 50, 100, or even 250 times more. No attack on China will fool anyone with half a brain about who is responsible for this.